1. Field of the Invention
The present invention relates to wheelchairs, and more particularly to a lightweight, folding wheelchair that due both to its weight and to the ease by which it may be collapsed and deployed, enables this wheelchair to be advantageously used in conjunction with other forms of private and public transportation for those persons requiring ambulatory assistance.
2. Description of the Prior Art
Built to support persons who have difficulty or are unable to walk, wheelchairs have traditionally been formed of steel pipes (tubes) arranged in a framework that is mounted on wheels. The steel pipes have provided a heavy, rigid, and stable support for the riders. In recent years, the number of persons suffering some degree of ambulatory incapacity has increased while, at the same time, a radical change has occurred with respect to the role of the handicapped in society. The handicapped have been included in the individual and minority rights movements of the past twenty years, resulting in a wide range of statutory regulations designed to increase opportunities for access and to enhance the mobility of the handicapped. Moving from a position "outside" of society, in the out-of-sight, out-of-mind category, the disabled and handicapped are being recognized as a valuable resource that must not be squandered due to artificial barriers.
Chief among these barriers has been the difficulty of the ambulatory disabled to fully make use of the elaborate public and private transportation system that is so much a part of both business and private life. Traditional wheelchairs with their weight and bulk, severely limit the ability of the disabled to travel. In response, many attempts have been made to produce "portable" wheelchairs by decreasing the weight and creating a lower profile with one of various types of folding mechanisms.
One of the more common folding wheelchairs provides a seat supported on a framework having a scissors-like bracing. Folding consists of collapsing the chair about a central pivot formed by the bracing, causing the vertical sides to come towards one another. This approach, in its permutations, is illustrated by Meyer (U.S. Pat. No. 3,627,343), Rodaway (U.S. Pat. No. 4,164,354) and Takeuchi, et al. (U.S. Pat. No. 4,457,535). Although the mechanism enabling its collapse can at times be ingenious in design, the structural framework for these chairs tended towards the traditional. These wheelchairs have continued to rely upon metal tubes for the framework. While the use of this material results in a sturdy folding wheelchair, it also results in a wheelchair that is generally too heavy to be of practical use while traveling.
Whether one is traveling on a plane, bus or other form of public transportation with a person requiring the assistance of a wheelchair, or in a private car, it is often necessary to assist that person to the vehicle and then to store the wheelchair during transit. In these instances, the wheelchair must be folded and carried to the storage location. The chore of carrying a heavy chair can rapidly become a problem, particularly when required to do so several times over the course of a day. The benefits of a lightweight wheelchair that provides ease in handling by even a small person, without undue strain, is readily apparent--whether over the course of a vacation or merely during an afternoon shopping excursion. In response, some use has recently been made of the "new," lightweight metal alloys, as, for example, in the sports wheelchairs. However, mere reduction in weight does not address another important design criteria for foldable wheelchairs.
In addition to reducing weight, it is also desirable to have a wheelchair that will fold into a small, non-bulky configuration that may be easily handled during transportaton and/or storage. Previous designs, using a hollow tubing and complex folding or support mechanisms to create a folding wheelchair, are of the type shown by Williams (U.S. Pat. No. 4,273,350) where a plurality of toggle braces (pivotal arms) are used to hold two opposite frames at a predetermined distance, and by Hale, et al. (U.S. Pat. No. 4,415,177) where a pivotal "spider mechanism" is utilized to fold the wheelchair. These and similar designs have achieved folding at the expense of an unwieldy folded end product. Attempts to reduce the bulkiness of the folded wheelchair have included wheelchairs that combine a scissors frame with a secondary folding process, as is illustrated by Lovell, et al. (U.S. Pat. No. 4,380,345) and Rothschild (U.S. Pat. No. 4,025,088). However these wheelchairs have only seemed to complicate the collapse and set-up operations, while doing little to decrease the "bulk" or increase the ease of handling of the collapsed chair.
In addition to being cumbersome to transport and store, the bulkiness of a wheelchair design also detrimentally affects the image or appearance projected by the wheelchair. The previous folding wheelchairs tended to evoke the images of a standard or medical wheelchair, of the type used by hospitals and found in traditional medical environments. While such wheelchairs are used by many people, this type of wheelchair tends to draw attention to the user, whether due to its intimidating manner or to the institutional connotations it evokes. People who might otherwise benefit from the use of a wheelchair--whether for certain specific activities or just on a temporary basis, will refrain from using a wheelchair because of a perceived stigma associated with such use. This can have the affect of functionally handicapping that person, where a "lower profile," i.e., less bulky wheelchair might prevent and/or avoid this situation in its entirety.
The bulky, portable wheelchairs produce a still further problem, one of even greater subtlety than the refusal to use a wheelchair based upon what others might think. Recent studies have shown that those persons suffering some form of disability carry a "burden of guilt" regarding the demands their condition places on the time and energy of their companions. A bulky portable wheelchair, by its weight and clumsiness, only aggravates this problem, resulting in a greater degree of isolation for that person than would otherwise be required by the disability.